yep, i am a big bloke 6.7-17 stone. the swingarm bearings sounds like it could be the course, i have just had it polished and i am now thinking that i mite not have put it back on right as for the tyres they where new 700 miles ago the pressures are ok. just had a look at the forks and the seals look fooked but thay are not leaking is it a job and a half to change them if not how much oil do you put in